9 



destroy all m^crobic life. By repeatedly boiling 

 fluids containiDET germs, with an interval of a day 

 or two between each boiling, to allow the spores 

 to germinat*', both Pasteur and Tyndall pucceeded 

 in destroying them. The lecturer next proceedt-d 

 to speak of the microb^^s in air. The systematic 

 examination of the atmospheric forms of bacteria 

 was first carried out on a scientific basis by the 

 great French chemist Pasteor, who, indeed, founded 

 the science ot bacteriology, and with whote name 

 some of the most marvellous and most beneficent 

 discoveries of the century will ever be assoctat*'d. 

 Before his researches on lerial microbes, some ^0 

 or 40 years ago, it was gp^nerally believed that the 

 lower forms of life, both animal and vegetable, 

 might arise spontaneously in certain highly 

 putrescible substances, such as vegetable in- 

 fusions, animal broths, decaying matters, and the 

 like Pasteur proved, by most ingenious exptri- 

 ments, that certain living germs, which are always 

 present in the atmosphere, were necessary for the 

 development of even the lowest forme of life. He 

 found that aftnr destroying the bacilli and th^ir 

 spores by repeated boiling, animal and vegetable 

 broths in small flasks, the necks of which were 

 drawn our to a fine thread, and subsequently 

 sealed, never developed living matter of any 

 kind, even after a very long period 

 of time. Thus he proved that all, even the 

 very minutest and simplest, forms of life, arose 

 from spores fioatmg in the air, and that there is 

 no origin of life apnrt from pre-existing germs. la 

 the course of his experiments, Pasteur found, by 

 expo-^iog ih^«e vegetable infusions in various 

 localities, ituit thn number of micro-organisms in 

 the air varied to an astonishing extent. Subse- 

 quent observers have extended this enquiry, and 

 with simiUr re.-^ults. Por instance, a given 

 ▼olame nt air tr )>u an inhabited room would con- 

 tain 10 000 living germs, the same from a city 

 street 4.(KJit, fr>m a city ptrk 450, from the mid- 

 Atlantic six, from a mountain peak only one. 

 After detailing Pome experiments by Professor 

 Frank land, whioh showed that the number of 

 microbes in fhe ntoi-t-phere was in direct propor- 

 tion to the D miliar of p rsons present in a room, 

 the lecturer fnvi : This leads me to a very inter- 

 esting and important brtnch of my subject. The 

 antiseptic trentrnt-nt of wounds and sargicnl 

 injuries, whinh is Associated with the great 

 and hononrnH ua-nn ot [lord Lister, is founded on 

 obsprv^itum >A' th« »<tfe'-ts of pRrfect cleanliness, 

 eombioHd with the protection from the injurious 

 contact of pntretyir.g organisms swarming 

 in the air. ! shall quote the words 

 of the CHlnhrHtMiJ (German savant. Professor 

 Virchww. <>n *' R't-ent advances in Science and 

 their b^ariri;; 'm lu-dicme and surgery " In 

 speaking "t thn aotisHpMc treatment he said: ''In 

 theci'y wh--re ^he nun snll lives and works who, 

 by dt-vieiotr this ti-'Htment, has introduced the 

 greate-t ami m .st l-eneficial reform that the 

 practical brnnches of mo<lern science have ev9r 

 known, ev;Ty»me •s »vvarn that Lord Lister, on the 

 strens; h of Ui^ oiiginHl reasoning, arrived at 

 practicnt resnivs whi -h the new theory of ferment- 

 ation and sept re pr*^ ►cesses has fully confirmed. 

 B*'fore anyouH had succeeded in demonstrating, 

 by exact methods, the microbes which are active 



in various diseases, or in showing the special 

 functions that they perform, Lister had learnt,. 

 in a truly prophetic revelation, the means by 

 which protection against the action of putrefying 

 organisms can be attained, and a perfect revolution 

 in the basis of surgical treatment has been the 

 consequence. Lord Lister is already, and will 

 always t>e. reckoned among the greatest benefac- 

 tors of the human race." After this magnificent 

 tribute to the genius of Lister, Professor Virchow 

 went on to say; "It has already happened once 

 before that an Englishman has succeeded in 

 producing, by artificial means, immunity from 

 disease, to the nearly complete destruction of at 

 Ir^ast one of the most deadly infectious diseases. 

 Jonner's notable discovery has stood its trial as 

 successtuUy, except, perhaps, in the popular fancy, 

 as ho could have hoped." As to bacteria in water, 

 Thames water, before filtration, contains on an 

 average, 20,000 bacteria in a cubic c*»ntim»tre 

 (about 20 drops). The effect of filtration 

 through uand, however, ie to deprive it of a 

 large portion of this microbic life, for afcer filtra- 

 tion it contains only 400 microbes in the cubic 

 centimetre. In deep water from the chalk, Frank- 

 land found only IS per cubio centimetre, and in 

 sea water a still less number ; while mud fiom the 

 sea bottom, and at the bottom of lakes, is very 

 rich in miciobic life. After carefully describing 

 the various methods of cultivating bacteria for 

 the purposes of observation and experiment, and 

 the means adopted for sterilising (or rendering 

 free from germ life) the various apparatus em- 

 ployed, the lecturer proceeded to give a description 

 of the methods of staining bacilli, by aniline dyes, 

 in order to bring their structural peculiarities 

 into greater prnminenc^^, and so to assist in their 

 minute examination. This process was illustrated 

 by some fine slides of various colourt-d forms The 

 lecturer then spoke of the bicteria t-erviceable to 

 men. Microbes and germs are usually associated 

 in the popular mind with disease. But tbe fact is, 

 by far the greater number of them aie useful to 

 man in a high degree, in the preservation of 

 h»*alth, in agriculture,and in certain manufactures. 

 They arfl Nature's scavengers, bringing about the 

 decay and disintegration of dead animal and 

 vegetable matter. Without their salutary 

 aid the surface of our earth would in 

 time be covered with the remains of plants 

 and animals, and life on this globe would ome to 

 an end, for it is by the decay and decomp >^ition of 

 dead and refuse animal and vegetable matter that 

 the fertility of the soil is maintained. Without 

 the aid of microbes, fertile land would th> n become 

 a dt'sert waste, incapable of sut'portin;; plant life. 

 And, of cours-e, without plant, life aniojaU must 

 necessarily cease to exist, for the herbivora w-.uld 

 starve for want of vegetable food, and the camivora 

 would also die for lack of animal food. In agri- 

 culture these minute germs subserve a doable 

 purpose, for they not only seize upon and devour, 

 so to speak, all d-ad matter, converting it into 

 simple chemical compounds suitable tor the sup- 

 port of vegetable life, but certain ol them possess 

 the property of converting atmospheric nitrogen 

 into nitric acid and nitrates. This very important 

 function of the bacteria has been on'y thoM-Ukihly 

 investigated lately. Farmers have long knowa 



